Maize commercial hybrids compared to improved population hybrids for grain yield and agronomic performance

Abstract

Improved maize (Zea mays L.) populations and population hybrids can both be profitable alternatives to commercial single-cross hybrids as well as good elite sources of diverse inbred lines. The objective of this research was to compare grain yield and agronomic performance between early maturing maize population hybrids and current early maturing commercial single-cross hybrids. This is a consequence of our research program targeted at identifying alternative heterotic patterns for the northern Corn Belt. Improved maize populations and population hybrids (S 0 generations) were evaluated in experiments arranged in randomized complete block and partially balanced lattice designs across 29 environments. Grain yield potential of population hybrids was optimally expressed under irrigated conditions. Data across environments showed that 20% of the population hybrids evaluated were not different (P ≤ 0.05) from at least one of the commercial single-cross hybrids for grain yield performance, root lodging, and stalk lodging percentages. The average mid-parent heterosis value across population hybrids from different geographic regions was 20.4% with negative estimates observed in only two population hybrids. Breeding efforts toward elite populations and population hybrids have demonstrated that germplasm improvement is extremely valuable and deserves public funding. These efforts should be supported in order to enable the development of elite sources of diverse inbred lines and the development of improved population hybrids for specific markets (e.g., organic) to increase producer options. Public maize breeding programs utilizing recurrent selection methods for germplasm improvement could address the need. These programs, however, should incorporate extensive testing of population hybrids.

Open-Pollinated vs. Hybrid Maize Cultivars

“…Sprague noted "it appears that the ear-to-row method of selection for yielding ability was discredited not because of genetic limitations of the method, but because of the inadequate field plot technique" [16]. Research after Richey's 1922 conclusion showed recurrent selection and varietal hybrids could be very successful at increasing maize yields after all, although they could not provide cultivars with the yields of the best hybrids [35,47,81,95,119,120,[126][127][128][129][130][131].…”

Germplasm enhancement for adaptation to climate changes

“…In the meantime, the NDSU program is helping produce a sustainable crop under intense drought for a better utilization by ethanol plants without additional transportation and fossil fuel costs. The NDSU maize population-hybrid concept has been recognized as a profitable alternative method of maize hybrid production (Carena 2005a, Carena andWicks III 2006) and it is currently being tested commercially in central and western ND for ethanol utilization.…”

Genetic divergence among maize hybrids by morphological descriptors

“…Therefore, improved maize populations allow the development of new lines with a good capacity of recombining amongst each other. In addition, there is the possibility of boasting more and more compensatory increments according to the breeding among divergent lines (Carena, 2005).…”